Bariatric surgery
Encyclopedia
Bariatric surgery includes a variety of procedures performed on people who are obese. Weight loss is achieved by reducing the size of the stomach with an implanted medical device (gastric banding) or through removal of a portion of the stomach (sleeve gastrectomy or biliopancreatic diversion with duodenal switch) or by resecting and re-routing the small intestines to a small stomach pouch (gastric bypass surgery
).
Long-term studies show the procedures cause significant long-term loss of weight, recovery from diabetes, improvement in cardiovascular risk factors, and a reduction in mortality of 23% from 40%. However, a study in Veterans Affairs (VA) patients has found no survival benefit associated with bariatric surgery among older, severely obese people when compared with usual care, at least out to seven years.
The U.S. National Institutes of Health recommends bariatric surgery for obese people with a body mass index (BMI)
of at least 40, and for people with BMI 35 and serious coexisting medical conditions such as diabetes. However, research is emerging that suggests bariatric surgery could be appropriate for those with a BMI of 35 to 40 with no comorbidities or a BMI of 30 to 35 with significant comorbidities.
concluded:
Recently the International Diabetes Federation issued a position statement in which "Under some
circumstances people with a BMI 30-35 should be eligible for surgery" International Diabetes Federation position statement on Bariatric Surgical and Procedural Interventions in the Treatment of Obese Patients with Type 2 Diabetes
When determining eligibility for bariatric surgery for extremely obese patients, psychiatric screening is critical; it is also critical for determining postoperative success. In patients with a body mass index of 40 kg/m2 or greater, there is a 5-fold risk of depression, and half of bariatric surgery candidates are depressed.
procedures, although they also reduce stomach size, these operations are based mainly on creating malabsorption.
(BPD/DS). Part of the stomach
is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine
is then connected to the pouch, bypassing the duodenum
and jejunum
.
In around 2% of patients there is severe malabsorption
and nutritional deficiency that requires restoration of the normal absorption. The malabsorptive effect of BPD is so potent that those who undergo the procedure must take vitamin
and dietary mineral
s above and beyond that of the normal population. Without these supplements, there is risk of serious deficiency diseases such as anemia
and osteoporosis
.
Because gallstone
s are a common complication of the rapid weight loss following any type of bariatric surgery, some surgeons remove the gallbladder
as a preventive measure during BPD. Others prefer to prescribe medication
s to reduce the risk of post-operative gallstones.
Far fewer surgeons perform BPD compared to other weight loss surgeries, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients.
A study on humans was done in Chile using the same technique however the results were not conclusive and the device had issues with migration and slipping. A study recently done in the Netherlands found a decrease of 5.5 BMI points in 3 months with an endoluminal sleeve.
, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach.
It is considered one of the safest procedures performed today with a mortality rate of 0.05%.
procedure in which the stomach
is reduced to about 15% of its original size, by surgical removal of a large portion of the stomach, following the major curve
. The open edges are then attached together (typically with surgical staple
s, sutures, or both) to leave the stomach shaped more like a tube, or a sleeve, with a banana shape. The procedure permanently reduces the size of the stomach. The procedure is performed laparoscopically and is not reversible.
This combined approach has tremendously decreased the risk of weight loss surgery for specific groups of patients, even when the risk of the two surgeries is added. Most patients can expect to lose 30 to 50% of their excess body weight over a 6 - 12 month period with the sleeve gastrectomy alone. The timing of the second procedure will vary according to the degree of weight loss, typically 6 – 18 months.
surgery where a sleeve is created by suturing rather than removing stomach tissue thus preserving its natural nutrient absorption capabilities. The procedure is producing some significant results that were published in a recent study in Bariatric Times and are based on post-operative outcomes for 66 patients (44 female) who had the gastric sleeve plication procedure between January 2007 and March 2010. Mean patient age was 34, with a mean BMI of 35. Follow-up visits for the assessment of safety and weight loss were scheduled at regular intervals in the postoperative period. No major complications were reported among the 66 patients. Weight loss outcomes are comparable to gastric bypass.
The study describes gastric sleeve plication (also referred to as gastric imbrication or laparoscopic greater curvature plication) as a restrictive technique that eliminates the complications associated with adjustable gastric banding and vertical sleeve gastrectomy
—it does this by creating restriction without the use of implants and without gastric resection (cutting) and staples.
is the Roux-en-Y gastric bypass. Here, a small stomach pouch is created with a stapler device, and connected to the distal small intestine. The upper part of the small intestine is then reattached in a Y-shaped configuration.
The gastric bypass had been the most commonly performed operation for weight loss in the United States, and approximately 140,000 gastric bypass procedures were performed in 2005, dwarfing the number of Lap-Band, duodenal switch and vertical banded gastroplasty procedures. The gastric bypass operation is considered the "gold standard" in the U.S.
A factor in the success of any bariatric surgery is strict post-surgical adherence to a healthier pattern of eating.
. The part of the stomach
along its greater curve is resected. The stomach is "tubulized" with a residual volume of about 150 ml. This volume reduction provides the food intake restriction component of this operation. This type of gastric resection is anatomically and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine
. The duodenum and the upper part of the small intestine are reattached to the rest at about 75–100 cm from the colon
.
of the stomach, which is interpreted by the brain to give a sense of satiety, or fullness. Early evidence suggests that it is less effective than other forms of bariatric surgery.
Post-surgery, overeating is curbed because exceeding the capacity of the stomach causes nausea
and vomiting
. Diet restrictions after recovery from surgery depend in part on the type of surgery. Many patients will need to take a daily multivitamin
pill for life to compensate for reduced absorption of essential nutrients. Because patients cannot eat a large quantity of food, physicians typically recommend a diet that is relatively high in protein and low in fats and alcohol
.
from University of California, Los Angeles
, reports the following weight loss at 36 months:
More recent studies have demonstrated that the medium (3–8 years) and long term (> 10 years) weight loss results for RYGB and LAGB become very similar. However, the range of excess weight loss for LAGB patients (25% to 80%) is much broader than that of RYGB patients (50% to 70%). Data (beyond 5 years) for sleeve gastrectomy indicates weight loss statistics similar to RYGB.
But long term effects are not clear.
In the Swedish prospective matched controlled trial, patients with a body mass index
(BMI) of 34 or more for men and 38 or more for women underwent various types of bariatric surgery and were followed for an average of 11 years. Surgery patients had a 23.7% reduction in mortality (5.0% vs. 6.3% control, adjusted hazard ratio 0.71). This means 75 patients must be treated to avoid one death after 11 years (number needed to treat
is 77).
In a Utah retrospective cohort study
that followed patients for an average of 7 years after various types of gastric bypass, surgery patients had 0.4% mortality while control patients had 0.6% mortality. Death rates were lower in the gastric bypass patients for all diseases combined, as well as for diabetes, heart disease and cancer. Deaths from accident and suicide were 58% higher in the surgery group.
A randomized, controlled trial in Australia compared laparoscopic adjustable gastric banding ("lap banding") with non-surgical therapy in 80 moderately obese adults (BMI 30-35). At 2 years, the surgically-treated group lost more weight (21.6% of initial weight vs. 5.5%) and had statistically significant improvement in blood pressure, measures of diabetic control, and high-density lipoprotein cholesterol. Post surgical complications included 1 patient with an infected surgical site, 4 with lap band malpositioning requiring laparoscopic revision, and 1 patient with cholecystitis
. In the non-surgical group, 12 patients declined or did not tolerate orlistat
or diet restrictions, and 4 patients developed acute cholecystitis.
Bariatric surgery in older patients has also been a topic of debate, centered on concerns for safety in this population. One study of elderly patients undergoing laparoscopic bariatric surgery at Mount Sinai Medical Center, however, reported 0% conversion to open surgery, 0% 30-day mortality, 7.3% complication rate, and average hospital stay of 2.8 days.
Post operative mortality from 0.1 - 2 %.
Given the remarkable rate of diabetes remission with bariatric surgery, there is considerable interest in offering this intervention to type 2 diabetes patients with a BMI of <35 kg/m2. Until high-quality, controlled trials are completed, appropriateness criteria (based on age, BMI, and the severity of eight obesity-related comorbidities) may be used to guide the careful selection of diabetes patients who may potentially benefit from bariatric surgery.
Laparoscopic bariatric surgery requires a hospital stay of only one or two days. Short-term complications from laparoscopic adjustable gastric banding are reported to be lower than laparoscopic Roux-en-Y surgery, and complications from laparoscopic Roux-en-Y surgery are lower than conventional (open) Roux-en-Y surgery.
in about 20% (bloating and diarrhea after eating, necessitating small meals or medication), leaks at the surgical site (12%), incisional hernia
(7%), infection
s (6%) and pneumonia
(4%). Mortality was 0.2%. As the rate of complications appears to be reduced when the procedure is performed by an experienced surgeon, guidelines recommend that surgery be performed in dedicated or experienced units.
Metabolic bone disease manifesting as osteopenia and secondary hyperparathyroidism
have been reported after Roux-en-Y gastric bypass surgery due to reduced calcium
absorption. The highest concentration of calcium transporters is in the duodenum. Since the ingested food will not pass through the duodenum after a bypass procedure, calcium levels in the blood may decrease, causing secondary hyperparathyroidism, increase in bone turnover, and a decrease in bone mass. Increased risk of fracture has also been linked to bariatric surgery.
Rapid weight loss after obesity surgery can contribute to the development of gallstones as well by increasing the lithogenicity of bile. Adverse effects on the kidneys have been studied. Hyperoxaluria that can potentially lead to oxalate nephropathy and irreversible renal failure is the most significant abnormality seen on urine chemistry studies.Rhabdomyolysis leading to acute kidney injury, and impaired renal handling of acid and base has been reported after bypass surgery.
Nutritional derangements due to deficiencies of micronutrients like iron, vitamin B12, fat
soluble vitamins, thiamine, and folate are especially common after malabsorptive
bariatric procedures. Seizures due to hyperinsulinemic hypoglycemia have been reported. Inappropriate insulin secretion secondary to islet cell hyperplasia, called
pancreatic nesidioblastosis, might explain this syndrome.
Gastric bypass surgery
Gastric bypass procedures are any of a group of similar operations that first divides the stomach into a small upper pouch and a much larger lower "remnant" pouch and then re-arranges the small intestine to allow both pouches to stay connected to it. Surgeons have developed several different ways...
).
Long-term studies show the procedures cause significant long-term loss of weight, recovery from diabetes, improvement in cardiovascular risk factors, and a reduction in mortality of 23% from 40%. However, a study in Veterans Affairs (VA) patients has found no survival benefit associated with bariatric surgery among older, severely obese people when compared with usual care, at least out to seven years.
The U.S. National Institutes of Health recommends bariatric surgery for obese people with a body mass index (BMI)
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
of at least 40, and for people with BMI 35 and serious coexisting medical conditions such as diabetes. However, research is emerging that suggests bariatric surgery could be appropriate for those with a BMI of 35 to 40 with no comorbidities or a BMI of 30 to 35 with significant comorbidities.
Indications
A medical guideline by the American College of PhysiciansAmerican College of Physicians
The American College of Physicians is a national organization of doctors of internal medicine —physicians who specialize in the prevention, detection, and treatment of illnesses in adults. With 130,000 members, ACP is the largest medical-specialty organization and second-largest physician group in...
concluded:
- "Surgery should be considered as a treatment option for patients with a BMIBody mass indexThe body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
of 40 kg/m2 or greater who instituted but failed an adequate exercise and dietDietingDieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
program (with or without adjunctive drug therapy) and who present with obesity-related comorbid conditions, such as hypertension, impaired glucose tolerance, diabetes mellitus, hyperlipidemia, and obstructive sleep apnea. A doctor–patient discussion of surgical options should include the long-term side effects, such as possible need for reoperation, gallbladder disease, and malabsorption." - "Patients should be referred to high-volume centers with surgeons experienced in bariatric surgery."
Recently the International Diabetes Federation issued a position statement in which "Under some
circumstances people with a BMI 30-35 should be eligible for surgery" International Diabetes Federation position statement on Bariatric Surgical and Procedural Interventions in the Treatment of Obese Patients with Type 2 Diabetes
When determining eligibility for bariatric surgery for extremely obese patients, psychiatric screening is critical; it is also critical for determining postoperative success. In patients with a body mass index of 40 kg/m2 or greater, there is a 5-fold risk of depression, and half of bariatric surgery candidates are depressed.
Classification of surgical procedures
Procedures can be grouped in three main categories: Standard of care in the United States and most of the industrialized world in 2009 is for laparoscopic as opposed to open procedures. Future trends are attempting to achieve similar or better results via endoscopic procedures.Predominantly malabsorptive procedures
Predominantly malabsorptiveMalabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
procedures, although they also reduce stomach size, these operations are based mainly on creating malabsorption.
Biliopancreatic diversion
This complex operation is termed biliopancreatic diversion (BPD) or the Scopinaro procedure. The original form of this procedure is now rarely performed because of problems with malnourishment. It has been replaced with a modification known as duodenal switchDuodenal switch
The duodenal switch procedure, also known as biliopancreatic diversion with duodenal switch or gastric reduction duodenal switch , is a weight loss surgery procedure that is composed of a restrictive and a malabsorptive aspect....
(BPD/DS). Part of the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
is then connected to the pouch, bypassing the duodenum
Duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
and jejunum
Jejunum
The jejunum is the middle section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms middle intestine or mid-gut may be used instead of jejunum.The jejunum lies between the duodenum...
.
In around 2% of patients there is severe malabsorption
Malabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
and nutritional deficiency that requires restoration of the normal absorption. The malabsorptive effect of BPD is so potent that those who undergo the procedure must take vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
and dietary mineral
Dietary mineral
Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine...
s above and beyond that of the normal population. Without these supplements, there is risk of serious deficiency diseases such as anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
and osteoporosis
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
.
Because gallstone
Gallstone
A gallstone is a crystalline concretion formed within the gallbladder by accretion of bile components. These calculi are formed in the gallbladder, but may pass distally into other parts of the biliary tract such as the cystic duct, common bile duct, pancreatic duct, or the ampulla of...
s are a common complication of the rapid weight loss following any type of bariatric surgery, some surgeons remove the gallbladder
Gallbladder
In vertebrates the gallbladder is a small organ that aids mainly in fat digestion and concentrates bile produced by the liver. In humans the loss of the gallbladder is usually easily tolerated....
as a preventive measure during BPD. Others prefer to prescribe medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s to reduce the risk of post-operative gallstones.
Far fewer surgeons perform BPD compared to other weight loss surgeries, in part because of the need for long-term nutritional follow-up and monitoring of BPD patients.
Endoluminal sleeve
A trial study performed on rats involved placing a 10 cm long impermeable sleeve into the rat's intestine to block absorption of food in the duodenum and upper jejunum. A study at Massachusetts General Hospital Weight Center and Gastrointestinal Unit found that rats who had the surgery ate 30% less food and lost 20% more weight than counterpart rats, while blood glucose levels returned to normal levels in all mice who had the surgery.A study on humans was done in Chile using the same technique however the results were not conclusive and the device had issues with migration and slipping. A study recently done in the Netherlands found a decrease of 5.5 BMI points in 3 months with an endoluminal sleeve.
Predominantly restrictive procedures
Procedures that are solely restrictive, act to reduce oral intake by limiting gastric volume, produces early satiety, and leave the alimentary canal in continuity, minimizing the risks of metabolic complications.Vertical banded gastroplasty
In the vertical banded gastroplastyVertical banded gastroplasty surgery
Vertical banded gastroplasty , also known as stomach stapling, is a restrictive operation for weight control. Both a band and staples are used to create a small stomach pouch...
, also called the Mason procedure or stomach stapling, a part of the stomach is permanently stapled to create a smaller pre-stomach pouch, which serves as the new stomach.
Adjustable gastric band
The restriction of the stomach also can be created using a silicone band, which can be adjusted by addition or removal of saline through a port placed just under the skin. This operation can be performed laparoscopically, and is commonly referred to as a "lap band". Weight loss is predominantly due to the restriction of nutrient intake that is created by the small gastric pouch and the narrow outlet.It is considered one of the safest procedures performed today with a mortality rate of 0.05%.
Sleeve gastrectomy
Sleeve gastrectomy, or gastric sleeve, is a surgical weight-lossWeight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
procedure in which the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
is reduced to about 15% of its original size, by surgical removal of a large portion of the stomach, following the major curve
Greater curvature of the stomach
The greater curvature of the stomach is directed mainly forward, and is four or five times as long as the lesser curvature.-Surface:Starting from the cardiac orifice at the incisura cardiaca, it forms an arch backward, upward, and to the left; the highest point of the convexity is on a level with...
. The open edges are then attached together (typically with surgical staple
Surgical staple
Surgical staples are specialized staples used in surgery in place of sutures to close skin wounds, connect or remove parts of the bowels or lungs. A more recent development, from the 1990s, uses clips instead of staples for some applications; this does not require the staple to penetrate.Stapling...
s, sutures, or both) to leave the stomach shaped more like a tube, or a sleeve, with a banana shape. The procedure permanently reduces the size of the stomach. The procedure is performed laparoscopically and is not reversible.
This combined approach has tremendously decreased the risk of weight loss surgery for specific groups of patients, even when the risk of the two surgeries is added. Most patients can expect to lose 30 to 50% of their excess body weight over a 6 - 12 month period with the sleeve gastrectomy alone. The timing of the second procedure will vary according to the degree of weight loss, typically 6 – 18 months.
- Stomach volume is reduced, but it tends to function normally so most food items can be consumed in small amounts.
- Removes the portion of the stomach that produces the hormones that stimulates hunger (Ghrelin), although the durability of this removal has yet to be confirmed.
- Dumping syndrome is less likely due to the preservation of the pylorus (although dumping can occur anytime stomach surgery takes place).
- Minimizes the chance of an ulcer occurring.
- By avoiding the intestinal bypass, the chance of intestinal obstruction (blockage), anemia, osteoporosis, protein deficiency and vitamin deficiency are significantly reduced.
- Very effective as a first stage procedure for high BMI patients (BMI >55 kg/m2).
- Limited results appear promising as a single stage procedure for low BMI patients (BMI 35–45 kg/m2).
- Appealing option for people with existing anemia, Crohn's disease, irritable bowel syndrome, and numerous other conditions that make them too high risk for intestinal bypass procedures.
Intragastric balloon (gastric balloon)
Intragastric balloon involves placing a deflated balloon into the stomach, and then filling it to decrease the amount of gastric space. The balloon can be left in the stomach for a maximum of 6 months and results in an average weight loss of 5-9 BMI over half a year. While not yet approved by the FDA the intragastric balloon is approved in Australia, Canada, Mexico, India and several European and South American countries. The intragastric balloon may be used prior to another bariatric surgery in order to assist the patient to reach a weight which is suitable for surgery, further it can also be used on several occasions if necessary.Gastric Plication
Basically, the procedure can best be understood as a version of the more popular gastric sleeve or gastrectomyGastrectomy
A gastrectomy is a partial or full surgical removal of the stomach.-Indications:Gastrectomies are performed to treat cancer and perforations of the stomach wall....
surgery where a sleeve is created by suturing rather than removing stomach tissue thus preserving its natural nutrient absorption capabilities. The procedure is producing some significant results that were published in a recent study in Bariatric Times and are based on post-operative outcomes for 66 patients (44 female) who had the gastric sleeve plication procedure between January 2007 and March 2010. Mean patient age was 34, with a mean BMI of 35. Follow-up visits for the assessment of safety and weight loss were scheduled at regular intervals in the postoperative period. No major complications were reported among the 66 patients. Weight loss outcomes are comparable to gastric bypass.
The study describes gastric sleeve plication (also referred to as gastric imbrication or laparoscopic greater curvature plication) as a restrictive technique that eliminates the complications associated with adjustable gastric banding and vertical sleeve gastrectomy
Sleeve gastrectomy
Sleeve gastrectomy is a surgical weight-loss procedure in which the stomach is reduced to about 25% of its original size, by surgical removal of a large portion of the stomach, following the major curve. The open edges are then attached together to form a sleeve or tube with a banana shape. The...
—it does this by creating restriction without the use of implants and without gastric resection (cutting) and staples.
Mixed procedures
Mixed procedures apply both techniques simultaneously.Gastric bypass surgery
A common form of gastric bypass surgeryGastric bypass surgery
Gastric bypass procedures are any of a group of similar operations that first divides the stomach into a small upper pouch and a much larger lower "remnant" pouch and then re-arranges the small intestine to allow both pouches to stay connected to it. Surgeons have developed several different ways...
is the Roux-en-Y gastric bypass. Here, a small stomach pouch is created with a stapler device, and connected to the distal small intestine. The upper part of the small intestine is then reattached in a Y-shaped configuration.
The gastric bypass had been the most commonly performed operation for weight loss in the United States, and approximately 140,000 gastric bypass procedures were performed in 2005, dwarfing the number of Lap-Band, duodenal switch and vertical banded gastroplasty procedures. The gastric bypass operation is considered the "gold standard" in the U.S.
A factor in the success of any bariatric surgery is strict post-surgical adherence to a healthier pattern of eating.
Sleeve gastrectomy with duodenal switch
A variation of the biliopancreatic diversion includes a duodenal switchDuodenal switch
The duodenal switch procedure, also known as biliopancreatic diversion with duodenal switch or gastric reduction duodenal switch , is a weight loss surgery procedure that is composed of a restrictive and a malabsorptive aspect....
. The part of the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
along its greater curve is resected. The stomach is "tubulized" with a residual volume of about 150 ml. This volume reduction provides the food intake restriction component of this operation. This type of gastric resection is anatomically and functionally irreversible. The stomach is then disconnected from the duodenum and connected to the distal part of the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
. The duodenum and the upper part of the small intestine are reattached to the rest at about 75–100 cm from the colon
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
.
Implantable gastric stimulation
This procedure where a device similar to a heart pacemaker is implanted by a surgeon, with the electrical leads stimulating the external surface of the stomach, is being studied in the USA. Electrical stimulation is thought to modify the activity of the enteric nervous systemEnteric nervous system
The enteric nervous system is a subdivision of the autonomic nervous system that directly controls the gastrointestinal system in vertebrates.It is derived from neural crest.-Function:...
of the stomach, which is interpreted by the brain to give a sense of satiety, or fullness. Early evidence suggests that it is less effective than other forms of bariatric surgery.
Eating after bariatric surgery
Immediately after bariatric surgery, the patient is restricted to a clear liquid diet, which includes foods such as clear broth, diluted fruit juices or sugar-free gelatin desserts. This diet is continued until the gastrointenstinal tract has recovered somewhat from the surgery. The next stage provides a blended or pureed sugar-free diet for at least two weeks. This may consist of skimmed milk, cream of wheat, a small pat of margarine, protein drinks, cream soup, pureed fruit and mashed potatoes with gravy.Post-surgery, overeating is curbed because exceeding the capacity of the stomach causes nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
and vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
. Diet restrictions after recovery from surgery depend in part on the type of surgery. Many patients will need to take a daily multivitamin
Multivitamin
A multivitamin is a preparation intended to supplement a human diet with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, and injectable formulations...
pill for life to compensate for reduced absorption of essential nutrients. Because patients cannot eat a large quantity of food, physicians typically recommend a diet that is relatively high in protein and low in fats and alcohol
Alcoholic beverage
An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...
.
Fluid recommendations
It is very common, within the first month post-surgery, for a patient to undergo volume depletion and dehydration. Patients have difficulty drinking the appropriate amount of fluids as they adapt to their new gastric volume. Limitations on oral fluid intake, reduced calorie intake, and a higher incidence of vomiting and diarrhea are all factors that have a significant contribution to dehydration. In order to prevent fluid volume depletion and dehydration, a minimum of 48-64 fl oz should be consumed by repetitive small sips all day.Weight loss
In general, the malabsorptive procedures lead to more weight loss than the restrictive procedures however, have a higher risk profile. A meta-analysisMeta-analysis
In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
from University of California, Los Angeles
University of California, Los Angeles
The University of California, Los Angeles is a public research university located in the Westwood neighborhood of Los Angeles, California, USA. It was founded in 1919 as the "Southern Branch" of the University of California and is the second oldest of the ten campuses...
, reports the following weight loss at 36 months:
- Biliopancreatic diversion - 117 Lbs / 53 kg
- Roux-en-Y gastric bypass (RYGB) - 90 Lbs / 41 kg
- Open - 95 Lbs/ 43 kg
- Laparoscopic - 84 Lbs / 38 kg
- Vertical banded gastroplasty - 71 Lbs / 32 kg
More recent studies have demonstrated that the medium (3–8 years) and long term (> 10 years) weight loss results for RYGB and LAGB become very similar. However, the range of excess weight loss for LAGB patients (25% to 80%) is much broader than that of RYGB patients (50% to 70%). Data (beyond 5 years) for sleeve gastrectomy indicates weight loss statistics similar to RYGB.
Reduced mortality and morbidity
Several recent studies report decrease in mortality and severity of medical conditions after bariatric surgery.But long term effects are not clear.
In the Swedish prospective matched controlled trial, patients with a body mass index
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
(BMI) of 34 or more for men and 38 or more for women underwent various types of bariatric surgery and were followed for an average of 11 years. Surgery patients had a 23.7% reduction in mortality (5.0% vs. 6.3% control, adjusted hazard ratio 0.71). This means 75 patients must be treated to avoid one death after 11 years (number needed to treat
Number needed to treat
The number needed to treat is an epidemiological measure used in assessing the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome...
is 77).
In a Utah retrospective cohort study
Cohort study
A cohort study or panel study is a form of longitudinal study used in medicine, social science, actuarial science, and ecology. It is an analysis of risk factors and follows a group of people who do not have the disease, and uses correlations to determine the absolute risk of subject contraction...
that followed patients for an average of 7 years after various types of gastric bypass, surgery patients had 0.4% mortality while control patients had 0.6% mortality. Death rates were lower in the gastric bypass patients for all diseases combined, as well as for diabetes, heart disease and cancer. Deaths from accident and suicide were 58% higher in the surgery group.
A randomized, controlled trial in Australia compared laparoscopic adjustable gastric banding ("lap banding") with non-surgical therapy in 80 moderately obese adults (BMI 30-35). At 2 years, the surgically-treated group lost more weight (21.6% of initial weight vs. 5.5%) and had statistically significant improvement in blood pressure, measures of diabetic control, and high-density lipoprotein cholesterol. Post surgical complications included 1 patient with an infected surgical site, 4 with lap band malpositioning requiring laparoscopic revision, and 1 patient with cholecystitis
Cholecystitis
-Signs and symptoms:Cholecystitis usually presents as a pain in the right upper quadrant. This is known as biliary colic. This is initially intermittent, but later usually presents as a constant, severe pain. During the initial stages, the pain may be felt in an area totally separate from the site...
. In the non-surgical group, 12 patients declined or did not tolerate orlistat
Orlistat
Orlistat , also known as tetrahydrolipstatin, is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake...
or diet restrictions, and 4 patients developed acute cholecystitis.
Bariatric surgery in older patients has also been a topic of debate, centered on concerns for safety in this population. One study of elderly patients undergoing laparoscopic bariatric surgery at Mount Sinai Medical Center, however, reported 0% conversion to open surgery, 0% 30-day mortality, 7.3% complication rate, and average hospital stay of 2.8 days.
Post operative mortality from 0.1 - 2 %.
Given the remarkable rate of diabetes remission with bariatric surgery, there is considerable interest in offering this intervention to type 2 diabetes patients with a BMI of <35 kg/m2. Until high-quality, controlled trials are completed, appropriateness criteria (based on age, BMI, and the severity of eight obesity-related comorbidities) may be used to guide the careful selection of diabetes patients who may potentially benefit from bariatric surgery.
Laparoscopic bariatric surgery requires a hospital stay of only one or two days. Short-term complications from laparoscopic adjustable gastric banding are reported to be lower than laparoscopic Roux-en-Y surgery, and complications from laparoscopic Roux-en-Y surgery are lower than conventional (open) Roux-en-Y surgery.
Adverse effects
Complications from weight loss surgery are frequent. A study of insurance claims of 2522 who had undergone bariatric surgery showed 21.9% complications during the initial hospital stay and a total of 40% risk of complications in the subsequent six months. This was more common in those over 40 and led to increased health care expenditure. Common problems were gastric dumping syndromeGastric dumping syndrome
Gastric dumping syndrome, or rapid gastric emptying is a condition where ingested foods bypass the stomach too rapidly and enter the small intestine largely undigested. It happens when the upper end of the small intestine, the duodenum, expands too quickly due to the presence of hyperosmolar food...
in about 20% (bloating and diarrhea after eating, necessitating small meals or medication), leaks at the surgical site (12%), incisional hernia
Incisional hernia
An incisional hernia occurs in an area of weakness caused by an incompletely-healed surgical wound. Since median incisions in the abdomen are frequent for abdominal exploratory surgery, ventral incisional hernias are termed ventral hernias. If it is not caused by an incision, then it is a...
(7%), infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s (6%) and pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
(4%). Mortality was 0.2%. As the rate of complications appears to be reduced when the procedure is performed by an experienced surgeon, guidelines recommend that surgery be performed in dedicated or experienced units.
Metabolic bone disease manifesting as osteopenia and secondary hyperparathyroidism
have been reported after Roux-en-Y gastric bypass surgery due to reduced calcium
absorption. The highest concentration of calcium transporters is in the duodenum. Since the ingested food will not pass through the duodenum after a bypass procedure, calcium levels in the blood may decrease, causing secondary hyperparathyroidism, increase in bone turnover, and a decrease in bone mass. Increased risk of fracture has also been linked to bariatric surgery.
Rapid weight loss after obesity surgery can contribute to the development of gallstones as well by increasing the lithogenicity of bile. Adverse effects on the kidneys have been studied. Hyperoxaluria that can potentially lead to oxalate nephropathy and irreversible renal failure is the most significant abnormality seen on urine chemistry studies.Rhabdomyolysis leading to acute kidney injury, and impaired renal handling of acid and base has been reported after bypass surgery.
Nutritional derangements due to deficiencies of micronutrients like iron, vitamin B12, fat
soluble vitamins, thiamine, and folate are especially common after malabsorptive
bariatric procedures. Seizures due to hyperinsulinemic hypoglycemia have been reported. Inappropriate insulin secretion secondary to islet cell hyperplasia, called
pancreatic nesidioblastosis, might explain this syndrome.